Vacuum flask



FIG. 1 is a top and front perspective view of a vacuum flask showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a front elevational view showing the vacuum flask in a disassembled state.

The rear elevational view is omitted because it is a mirror image of the front elevational view.

The right side view is omitted because it is a mirror image of the left side view. 

CLAIM The ornamental design for a vacuum flask, as shown and described. 